1. Field of the Invention
The present invention relates, in general, to a method of fully freezing ice and a refrigerator using the same, more particularly, to a method of fully freezing ice and a refrigerator using such method, in which fully-frozen ice can be provided at lower ambient temperatures.
2. Description of the Related Art
A refrigerator is an apparatus where various foods remain fresh for an extended period of time, using air heat-exchanged in an evaporator during a freezing cycle. Such refrigerators include a freezer for storing frozen foods such as meat and fish below their freezing temperature, and a cold storage for storing cold-storage foods such as fruits and vegetables above their freezing temperature.
In general, a freezer 20 is provided at its upper portion with an ice-maker 40 supplied with water from the outside for making ice, and an ice-storage 30 for storing the ice transferred from the ice-maker 40. Referring to FIG. 1, the ice-making and ice-transferring procedures will be explained. First, water is supplied from an external water supply via a water-supply valve (not shown) and a water-supply tube 45 to an ice-making tray 41. The supplied water starts to be frozen by cold air in the freezer 20. Below the ice-making tray 41 is provided an ice-making temperature sensor 80 for detecting the temperature of the ice-making tray 41. If the temperature of the ice-making tray 41 reaches a pre-determined fully-frozen temperature, the ice-making procedures are completed and, after a desired period of ice-transfer standby time, the ice is transferred. An ice-transfer motor 47 is provided at one side of the ice-making tray 41. The ice-transfer motor 47 turns the ice-making tray 41 at a certain angle to allow the frozen ice to be transferred into the ice-storage 30. On the other hand, at the other side of the ice-making tray 41 is provided an ice-full sensing lever for sensing the quantity of ice stored in the ice-storage 30.
In the conventional refrigerator described above, however, whether the frozen ice is to be transferred is determined considering only the temperature of the ice-making tray. Thus, a problem occurs that the ice is transferred from the ice-making tray even when it is not completely frozen, depending upon ambient temperature. This phenomenon occurs because, in a case of a lower ambient temperature, even if the compressor of the refrigerator is operated for a relatively short period of time, the controlled temperature of the freezer can be easily met. Therefore, the ice is transferred before it is fully frozen, in particular, before the inside thereof is not completely frozen, thereby degrading the ice quality. In addition, when the not-fully frozen ice drops into the ice storage, it is likely to be broken and stick together inside the ice storage.